While visiting our blog, you have also been checking out older posts. Our second most popular post viewed in 2018 was a 2014 post, Identifying Your Pest – with Poop?. There are a lot of budding scatologists out there.

Other IPM Blogs – Besides ThinkIPM, we have more dedicated blogs, and you don’t need to be a specialist to subscribe to them. Here are some of the more popular posts:

Our new Spotted Lanternfly video, Have YOU Spotted Lanternfly Egg Masses was just posted, but it has already reached the number two spot. This invasive insect is getting a lot of attention and we need your help to keep track of it in New York.

Plumbing issues lead to pest problems — there’s little doubt about that. Leaks offer standing water to rodents, and clogged, scummy drains are breeding sites for flies. How curious that one of the most common plumbing-related pest problems I see is drains and pipes without water.

Unused, uncapped drains are an open door for cockroaches and more.

Case Study
At a multi-story office building, workers reported the presence of waterbugs, aka American cockroaches, on unconnected floors. Sanitation at the site was great, and no obvious leak created harborage for cockroaches: both excellent IPM practices. But a thorough inspection uncovered an unused bathroom on one floor where the water had been shut off during renovation. Not only could we smell sewer gasses — this bathroom contained several dead American cockroaches, suggesting this was the source for that floor. On another floor a drainpipe in a mop closet was open, and we could see cockroach frass.

A drain trap — and never mind the large gap at the wall. Exclusion is a whole different matter.

Plumbing Traps 101
If you’ve ever looked under a sink, you’re familiar with a plumbing trap: that U-shaped pipe that changes the flow of water from vertical to horizontal. Its job: to create a water seal that prevents odors and harmful sewer gasses from escaping into the living or work space. Each time the drain is used, fresh water replaces standing water in the trap to maintain a permanent seal.

Uncapped, unused — except as a highway for pests.

As side benefit, this design deters pests from using pipes to move within or between buildings. Sure, cockroaches and rodents (especially rats) can overcome plumbing traps by crawling through a small amount of water (see National Geographic video on rats in toilets). But when drains are regularly used, they’re unlikely to harbor pests.

Drain Fails
Problems with trap seals occur when drains are infrequently used and water evaporates over time, or if drains are clogged with debris. Floor drains are susceptible to drying out if

Inspection Tips and Solutions
Another core IPM practice: owners or facilities maintenance personnel need to check drains often to verify that water is present in the trap. Check them each time floors are cleaned. For traps that have dried out the solution is easy – pour water down the drain until the trap is full. While you’re at it, make sure that drains are clear of debris. If the pipe is cut and no longer used, cap the end for a permanent seal.

Why? To start, let’s consider the distinction between an inspection and monitoring. An inspection is a view of pest activity at that moment in time. But what if pests are only active at night? Or on weekends when the building is quiet? Thus, monitoring is a record of pest activity in the times that you are not present.

Integrated Pest Management, or IPM, is a decision making process that uses information about pest populations to decide how to manage them. Monitoring is a critical step in IPM programs that offers valuable insights:

1. Species Identification: insect monitors intercept pests, allowing a trained professional to identify them. In turn, identification provides information about preferred harborage, food and water sources.

2. Early Detection: monitors can intercept pests that are present at low levels, and can help identify a problem before it gets out of hand.

3. Directionality: monitors can provide information about pest directionality: where are they coming from [harborage] and where they are going [food locations]. Monitors might also provide clues about non-obvious pathways, such as overhead areas (Figure 1).

Fig. 1. This firebrat likely fell onto the monitor from above.

4. Age of Population: rodent bait stations can contain informative evidence (Figure 2). Are droppings all one size, or are they mixed sizes, suggesting the presence of different age groups? Are droppings black, meaning that they are visiting the station for the first time, or are some droppings the color of the bait, suggesting multiple feedings?

Fig. 2. Mixed large and small droppings suggest adult and juvenile feeding; mostly black droppings suggest this is the rodents first feeding.

Parasitoids, predators and secondary pests can also tell you about the age of the infestation (Figure 3). Ensign wasps are egg-case parasitoids of American cockroaches. Their presence suggests that the cockroaches are actively reproducing nearby, whereas secondary pests may indicate the presence of old bait or pest carcasses.

5. Proximity to Harborage: juvenile pests, including rodents and cockroaches, stay close the harborage. Intercepting them on monitors can narrow your search to nearby areas for identifying the harborage (Figure 4).

6. Management Efforts: some monitors might contain evidence about recent control efforts (Figure 4). Finding German cockroaches with crinkled wings is a sign that they have been treated with an insect growth regulator. But what if you didn’t apply this kind of product? Perhaps the cockroaches are coming from a neighboring area.

Fig. 4. Nymph (1) and adult (2) German cockroaches on an insect monitor. The arrow indicates the location of crinkled wings from treatment with an insect growth regulator.

Effective monitoring programs provide good coverage of pest vulnerable areas. The location of monitoring devices are recorded on a facility map, and a pest catch log records the number of pests caught on each monitor. These specifications allow the pest professional to collect enough information to determine if a treatment is needed, where to focus efforts and what treatment should be applied.

When preparing for any job, my dad will remind me to choose the right tool for the task. In a way, this is an extension of another one of his gems: work smarter, not harder. Selecting the right tool can increase your efficiency and help you to get the job done correctly. Time and again I have reaped the benefits of this wisdom.

On a recent inspection of a food service establishment, management informed me that they had seen a small rat in the service hallway. Traps had been placed by the pest professional, but as of yet, the stealthy rat had not been caught. My interest was piqued.

Tripped trap with piece of rodent tail

In the hallway I found that several rat snap traps had been baited and placed along the wall where the rat had been observed. One trap had been tripped, and actually had a small piece of the rodent’s tail attached, which seemed rather odd. How would a rat trigger the trap and get only its tail caught? That is when the real detective work started.

No droppings were present along this runway to help with identification, but the now short-tailed rodent had fed on the bait, leaving behind impressions of its teeth. I pulled out my ruler and found that the pair of teeth were less than 2mm wide, which is suggestive of mice. Indeed, mice tend to leave impressions that are 1 to 2mm wide, while a pair of teeth for rats tends to be 3.5 to 4mm wide. Now the pieces of this mystery were adding up. A small rat was not the culprit, but rather a mouse. The traps had not been effective (except for taking off a piece of tail) because mice are unlikely to exert enough force on the trigger to engage a rat trap. So, what is the right tool for this task? You guessed it, a mouse trap!

Did you know…

The term rodent (the group that includes mice, rats and their relatives) is a derivative of the Latin word rodere, which means “to gnaw.” Rodents gnaw on objects to obtain resources, in the process wearing down their teeth. In fact, rat teeth grow approximately 5 inches per year, and are kept short by their gnawing behavior or by grinding their teeth.

Peanut butter is a staple in managing mice and rats, especially in residential settings. It’s easy to apply to traps, it stays fresh for several days — and a jar of peanut butter has a long shelf life. But peanut butter isn’t always your best bet. Because sometimes that peanut butter is a magnet for other pests — think cockroaches and ants. Besides, a large rodent population might have a wide range of food preferences. And for some, peanut butter might not be at the top of the list.

For those situations, here’s a trick that could help — bait those traps with string! String? Here’s why:

String tied to the paddle of a snap trap is a baiting technique that doesn’t feed other pests.

Females can give birth to six to eight litters of pups throughout the year, though they breed more often when it’s warm. They work hard at building nests for their young, and among their favorite nesting materials is string. So just tie a short piece string or dental floss tightly to the paddle of a snap trap and there’s your bait. Be sure to loop your string closely around the base of the paddle. And this is one bait that’ll never spoil.

Are subway rats really the size of house cats? Are there American cockroaches or “waterbugs” as big as your hand? Fortunately, neither is true. But a 2012 study offers insight as to why those beliefs exist.

First, some background. Whenever I give a presentation about structural pests, I like to bring some specimens along for show and tell. Invariably, as I open up a box of pinned insect specimens someone says, “I’ve seen cockroaches twice that big!” Outwardly I might act surprised, but that’s because I’m thinking, “Hmm. I’ve been in some sketchy places and seen some nasty things, but the American cockroach is usually about 1.5 inches long, and the average Norway rat is about 16 inches from nose to tail and weighs about 12 ounces.”

Sure, there are exceptions — some can be smaller, others larger, but a three-inch-long cockroach? Surely there’s an explanation.

Then one day I stumbled on a post by ABC News: “Spiders Appear Bigger When You Fear Them” — and it all started to make sense. According to an Ohio State study, being scared can cause an individual to exaggerate the size of the object they fear. A rat racing past you on the subway is sure to induce fear, as is a cockroach in your bathroom. But looking at a dead cockroach, pinned in some entomologist’s specimen box? That’s not so scary.

A challenge: next time you see a critter that would normally make you afraid, take a closer look. You might find that your perception of their size more accurately represents their true size — which in all cases is large enough!

Snout to tail, your average Norway rat is 16 inches long and weighs in at about 12 ounces. Cats? A healthy weight for a small breeds is around 5 pounds; the very largest, 18 pounds.

Whether you are dealing with a pest problem, having car trouble, or trying to figure out who stole the cookie from the cookie jar, your job starts with an investigation — the information-gathering step where you search for clues. In pest management, inspection is the first and most important step toward addressing an issue, helping you discover what pest species are present — and why.

Here’s the scene: you’re inspecting a dark basement and happen upon some droppings. If from a rodent, your next step might be to look for more droppings, sebum trails (oily marks) that show where rodents have traveled, or chew marks. These clues help you determine how rodents are entering the building and where they are finding food, water and shelter. But fi the droppings are from cockroaches, your inspection will shift to looking for wet, decaying organic material and harborage areas.

For pest ID at work or at home, your eyes are your best tools — helped, perhaps, by a magnifying lens.

But how do you tell the difference between the droppings?

Rodents dropping are relatively smooth and often pointed or tapered at one end Mice are smaller critters, so their droppings are typically less than ¼ inch long, whereas rat droppings are larger than 1/3 inch. Rodent droppings might also contain hair — rodents swallow it as they groom themselves.

Like other insects, cockroaches have structures called rectal pads that are used to absorb water and nutrients before their poop leaves their bodies. The orientation and shape of these pads gives insect droppings unique shapes. In the case of cockroaches, droppings appear to have ridges. For more information, see this pictorial key to rodents.

By conducting a thorough inspection and correctly identifying pests, you can develop an action plan to reduce their populations and prevent them from coming back.

Spring! Time to fling open the windows, plant some flowers — and begin the annual tradition of spring-cleaning. But are you getting to all those places where pests find food, water, or shelter? Householders tend to overlook these five places. And they could be just the spots where pests come for a free meal or to catch a few zzzz’s.

Clean these often:

The Stove Top — or rather, the space right beneath it

Stove Top

Most cooks wipe down the top of the stove when they’ve fixed a meal. But what about the space under the stove lid? Here, spilled liquids, crumbs and other food materials can accumulate out of sight, providing food for rodents, cockroaches, and other pests.

Counter-Top Ledges

Counter-top Ledges

Crumbs, spilled coffee, whatever — they’re easy to see and clean up on your countertops. But food particles and liquid can accumulate on the undersides of ledges too. So while you’re at it, wipe down those ledge undersides.

The Toaster

Toaster

Toasters and toaster ovens are great hidey-holes for crumbs. Lots of crumbs. Just be safe when you clean — unplug the toaster. Then pull out the tray and wash it. For even better results, invert the device to shake out the crumbs or go at it with your vacuum cleaner.

Behind the Faucet

Behind the Faucet

The sink is our go-to place for cleaning dishes and utensils. But how often do we remember to clean behind the faucet or around its handles? Here, water and spilled food particles could make for the pest equivalent of the soup kitchen if not cleaned regularly.

The Trash Receptacle

Trash Receptacle

Let’s face it — plastic bags are easy to tear. Too often, something we toss out tears the bag; then the combination of (for instance) food scraps and wet coffee ground means we’ve got stuff leaking out. The solution? Clean the receptacle when you take out the trash.

Neither snow nor rain nor heat nor gloom of night will stop Norway rats from finding a bite — to eat! With bitter cold and more than 55 inches of snow (and counting), winter in New York City has been memorable. More than ever, rats need to find a way — and their wayfinding signs are unmistakable. Brown droppings cast against a gritty ice pile, footprints in untouched snow, and tunnels leading under dumpsters with the unmistakable sebum trail — grease marks from protective oils on rodent fur — demonstrate that the rat will prevail and that life finds a way.